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Updated: Nov 28, 2025
Establishment of A Mouse Model of Aqueous Deficiency Dry Eye
Published on: November 1, 2024
Effect of IRT5 probiotics on dry eye in the experimental dry eye mouse model
Jayoon Moon1,2, Jin Suk Ryu2, Jun Yeop Kim2
1Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.
Objective:
To investigate the clinical effects of IRT5 probiotics in the environmental dry eye model.
Methods:
Eight week old male C57BL/6 mice were randomly divided into two groups; control group (n = 16) received oral gavage of 300 μL phosphate-buffered saline (PBS) alone once daily, IRT5 group (n = 9) received oral gavage of 1 x 109 CFU IRT5 probiotics powder in 300 μL PBS once daily, both groups for 11 to 12 days. Simultaneously, all mice underwent dry eye induction. Tear secretion, corneal staining and conjunctival goblet cell density were evaluated. Quantative real-time polymerase chain reaction (RT-PCR) for inflammation-related markers was performed. 16S ribosomal RNA of fecal microbiome was analyzed and compositional difference, alpha and beta diversities were assessed.
Results:
There was no difference in NEI score but significant increase in tear secretion was observed in IRT5 group (p < 0.001). There was no significant difference in goblet cell density between groups. Quantative RT-PCR of cornea and conjunctiva revealed increased TNF-α expression in IRT5 group (p < 0.001) whereas other markers did not significantly differ from control. IRT5 group had significantly increased species diversity by Shannon index (p = 0.041). Beta diversity of genus by UniFrac principle coordinates analysis showed significant distance between groups (p = 0.001). Compositional differences between groups were observed and some were significantly associated with tear secretion. Multivariate linear regression analysis revealed Christensenellaceae (p = 0.009), Lactobacillus Helveticus group (p = 0.002) and PAC001797_s (p = 0.011) to strongly influence tear secretion.
Conclusion:
In experimental dry eye model, IRT5 probiotics treatment partially improves experimental dry eye by increasing tear secretion which was associated with and influenced by the change in intestinal microbiome. Also, intestinal microbiome may affect the lacrimal gland through a different mechanism other than regulating inflammation.
Insights
IRT5 probiotics improved experimental dry eye by increasing tear secretion, linked to gut microbiome changes. This suggests the gut microbiome may influence lacrimal glands independently of inflammation.
Area of Science:
- Ophthalmology
- Microbiology
- Immunology
Background:
- Dry eye disease (DED) is a prevalent condition affecting ocular surface health.
- Environmental factors can exacerbate DED, necessitating novel therapeutic approaches.
- The gut-eye axis is an emerging area of research with potential implications for ocular diseases.
Purpose of the Study:
- To evaluate the efficacy of IRT5 probiotics in an experimental dry eye model.
- To investigate the impact of IRT5 on tear secretion, corneal health, and ocular inflammation.
- To explore the relationship between gut microbiome alterations and dry eye parameters following IRT5 administration.
Main Methods:
- C57BL/6 mice were subjected to dry eye induction and treated with either IRT5 probiotics or phosphate-buffered saline (PBS).
- Tear secretion, corneal staining, and goblet cell density were assessed.
- Quantitative real-time PCR (RT-PCR) was used to analyze inflammation markers.
- Fecal microbiome analysis (16S rRNA sequencing) was performed to evaluate diversity and composition.
Main Results:
- IRT5 treatment significantly increased tear secretion (p < 0.001) without altering corneal staining or goblet cell density.
- Tumor necrosis factor-alpha (TNF-α) expression was elevated in the cornea and conjunctiva of the IRT5 group (p < 0.001).
- Significant increases in gut microbial species diversity (Shannon index, p = 0.041) and distinct community structures (beta diversity, p = 0.001) were observed in the IRT5 group.
- Specific bacterial taxa, including Christensenellaceae, Lactobacillus Helveticus group, and PAC001797_s, were strongly associated with improved tear secretion.
Conclusions:
- IRT5 probiotics partially ameliorate experimental dry eye by enhancing tear secretion.
- Changes in the intestinal microbiome composition and diversity induced by IRT5 are associated with improved tear secretion.
- The gut microbiome may influence lacrimal gland function through mechanisms independent of direct ocular inflammation regulation.
